The internal affairs investigation into Graham's conduct began after the state police were made aware of the trooper's posts by people upset about the comments, Waterman said. Graham, a 16-year veteran, was assigned to the Rockingham barracks.

An initial review of the case by the Internal Affairs Department showed that many of the social media posts in question were "egregious, and rose to a level of extreme concern for the Vermont State Police," Waterman said. Potential violations of the state police Social Media Policy and the Code of Conduct were the focus of the investigation.

Graham had been notified of the evidence that supported continued department action against him, Waterman said.

In a statement released Thursday afternoon, L'Esperance apologized to anyone offended by Graham's posts.

"I accept Jon Graham's resignation for all citizens who expect and have a right to a fair and impartial state police force," L'Esperance said in the statement. "I also accept Jon Graham's resignation for all Vermont State Troopers who selflessly serve our communities and commit at the beginning of every shift to enforce the laws of our state without bias or prejudice, no matter their personal beliefs. I believe strongly that we are accountable for our actions. I commit the Vermont State Police to continue to build the community's faith in this department."

Graham is the second Vermont State Police employee in recent months to resign amidst concerns about conduct.

Trooper Eric Rademacher, accused of driving under the influence of alcohol while on duty, also resigned his post on April 15. Rademacher, 27, of Mendon worked out of the Rutland barracks, and he faces criminal charges following allegations that arose in early March.